Input: A matrix M over some field F and integers r,k.Parameter: r,kQuestion: Can we alter at most k entries in M such that rank of the edited matrix becomes at most r ?

We study the question for an arbitrary matrix over a given field F, where F is either a finite prime sized field or the field of reals. This problem corresponds to the decision version of the classical matrix rigidity problem. We considered the parameter to be r+k. We showed that this problem is fixed parameter tractable wrt r+k. We also show that this problem is W[1] hard with respect to k, i.e. it does not admit any algorithm of the form f(k) * poly(input size) under some widely held assumptions.